Active Site Studies to Explain Kinetics of Lipas`s in Organic Solvents Using Molecular Dynamics Simulations

Area of Science:

• Biochemistry and enzymology
• Computational chemistry
• Organic chemistry

Background:

• Enzyme performance in non-aqueous media is crucial for industrial biocatalysis.
• Understanding lipase behavior in organic solvents requires detailed molecular insights.
• Previous studies often relied on single parameters, limiting predictive power.

Purpose of the Study:

• To investigate the molecular dynamics governing lipase activity in various organic solvents.
• To correlate enzyme kinetics with computational simulations for three distinct lipases.
• To identify key factors influencing lipase performance across different solvent environments.

Main Methods:

• Comprehensive molecular dynamics (MD) simulations of three lipases (CALB, RML, TLL).
• Enzyme kinetics experiments in acetonitrile, MTBE, and hexane with varying water activity.
• Analysis of water cluster formation and active site conformation/stability.

Main Results:

• No single criterion predicts lipase activity in organic solvents.
• Candida antarctica lipase B (CALB) activity negatively correlates with surface water clusters.
• Rhizomucor miehei lipase (RML) and Thermomyces lanuginosus lipase (TLL) activities depend on active site conformation and stability, not high water activity.

Conclusions:

• Lipase performance in organic solvents is multifactorial, requiring a holistic assessment.
• Tailoring lipase applications necessitates considering specific enzyme-lipase-solvent interactions.
• Understanding water dynamics and active site integrity is vital for enzyme engineering.